The omissions raise questions about the Pennsylvania government's connection to the oil and gas industry, which has a vested interest in the natural gas trapped in the Marcellus Shale beneath Pennsylvania and three other states.

Seven plaintiffs brought a lawsuit against companies serving the gas industry that claims natural gas extraction by hydraulic fracturing, or fracking, within a mile of their homes in southwestern Pennsylvania contaminated their drinking water and caused serious illnesses.

Toxicology tests on the plaintiffs found the presence of toluene, benzene and arsenic in their bodies, according to the complaint.

Toluene and benzene, commonly used in fracking, are called BTEX compounds and are listed as contaminants in the Safe Drinking Water Act. Benzene and arsenic are known human carcinogens.

A spokesman for the Pennsylvania Department of Environmental Protection (PDEP) told the Times that oil and gas division officials only wanted to see the results they deemed relevant to determining whether drinking water was being contaminated, and that the remaining metals were below federal standards or had no standards attached to them.

Kendra Smith, a lawyer for one of the plaintiffs, countered that some of the 14 metals not reported in her client's tests have already been identified by industry studies as contaminants in water produced from oil and gas operations.

Smith told the Times that it could only be a "deliberate procedure” by the oil and gas division and the Bureau of Laboratories “to withhold critical water testing results.”

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Low ppm readings should still be reported because they are part of the analysis. While some will argue that below a certain level, these chemicals are "harmless", one should not be cherry picking data in a scientific study. Also, low readings or not, what are those chemicals doing there? Were they there before? Do they occur naturally in the water table? I kind of doubt that. And, what will the readings be two years from now? Nothing short of full disclosure is acceptable when it comes to whether or not our water table is being compromised.